Photographic color couplers containing mono-n-alkyl groups



United States PatentO PHOTOGRAPHIC COLOR COUPLERS CONTAIN- .1 :1. 1. .IING MoNoanl-ALK LlGRou Walter M. Bush, Ilmari F, Salminen, and John R. Thirtle, Rochester; N.Y;, 'assignors' to Eastman Kodak Com. A a m Rochester, N.Y.,'"a corporation ol New Jersey 7 No Drawing. Application July 25, 1956 v (Serial No. 599,895

9 Claims. ((31596-100) This invention relates to colorfphotography and particularly to photographiccolor formers containing normal alk ylgroups.

,The formation of colored photographic images by cou- "pling the development product of primary aromatic amino developingagents with color-forming or coupling compounds is well known. In theseprocesses the subtractive process of color formation, is ordinarily used and the image dyes are of the complementary primary colors cyan, magenta and yellow. The-.couplers-usedto produce these .dYes generally contain .color forming groups of the phenolic hydroxyl, pyrazolone. or benzoyl, acetamide .pling with the oxidationproduct .ofthe primary aromatic amino deyelopingagent .-on photographic development;

Whcnfihesecolonforming compoundsare incorporated .inlthe sil yer halide emulsion layer prior tophotographic development, they usually contain groups which render non difiusing .in-theemulsion layer. Tertiary amyl and othersbranched chain alkyl radicals have been used for this purposeand normal allryl radicals attached to nitrogen or oxygenatoms-have also been employed.

,One rofthe disadvantages of the tertiary amyland other .b ranched chain alkyl radicals in color-forming compounds .is that they raise the melting point of the .cquplerand thus. increase its tendency to crystallize in the emulsion. They are also usually of limited solubility" in organic, solvents and the amount which can be incorporatedinitheemulsion layer is therefore limited.-

It ish-therefore an object vof the present invention to provide novel photographic .coupler compounds for incorporation in silver halide emulsion layers. A further object istotprovide coupler compounds having lower melting points than those hitherto employed and therefore having lower tendencyto crystallize in theemulsion.

1A; 1-sti1l further object is. to provide coupler compounds which are more soluble inorganic solvents than-those 2,908,573 Pzitented Oct. 13, 1959 '2 oxidation product of a primary aromatic amino developing agent, and which includes one or more aryl-radicals, R is hydrogen or an ethyl radical, R is a normal alkyl radical containing from 7 to 15 carbon atoms, for ex-. ample, a normal heptyl, normal octyl, normal nonyl,

normal tridecyl or normal pentadecyl radical in the ortho, it meta or para position, and n is O, 1 or 2.

.classes, These groups render the couplercapable of couhithertoemployed; thus permitting higher concentrations .of coupler to be used'and higher dye densities tobe lobtained, A still further object is to provide coupler compounds which havelower diffusivity in theetnulsion layer than those previonslyemployed. Other objects will appearrfrom the following description of our invention.

These objects are accomplished according to our invention by the meet couplers containing a single normal alkyl radical attached to an aryl radical, especially toa phenoxy lacylamino radical. Couplers which wepropose to usehave one ,of; the following structuresz. l

. in whichi'Z-is vaph enp lichydr cnryl, ipyra zolone orben zoyl ae am d t 1uP:Whi9h-. ist 'ap ley fcoupli g withthe 1 l.

More specifically, the classes of color-forming compounds which we employ have one of the following structures:

(II) I 0 R o1 NHC ohmornmQ on 01 N=CNHCO no CIQN/ l CO H,

9 9 7 in which one X isihydrogen and the other X is and in which R, R and n are the same as above.

Typical couplers which we may use according to our invention are as follows:

(11) Ca I The couplers of our invention were prepared as follows:

No. 1: a-(3-n-pentadecylphenoxy)acetic acid.+A mixture of 25.2 g. (0.1 mole) of 3-n-pentadecylphenol, 6 .0 g. (0.11 mole) of potassium hydroxide pellets, and 150 cc. of xylene was stirred and boiled until 75 cc. of wet xylene had been collected. An additional cc. of xylene was added and the process continued until a total of cc. had been collected. To the solution was added 11.6 g. (0.1 mole) of sodium chloroacetate, and stirring and refluxing were continued for 3 hours. The mixture was cooled to room temperature and acidified with 25 cc. of hydrochloric acid and 50 cc. of ice water. The solid was collected, washed, and then dissolved in 600 cc. of ether,

from which it separated on concentration. Crystallization from a mixture of ligroin and benzene gave a mate rial which melted at 99100 C.

a-(3-n-pentadecylphen0xy)acetyl chloride.-A mixture of a-(3-n-pentadecylphenoxy)acetic acid and an excess of thionyl chloride was heated at 50-56 for 4 hours. The excess thionyl chloride was removed under vacuum and the solid residue was used directly in the next step.

2,4-dichl0r0 3-methyl-6-[a (3 n-pentadecylphenoxy)- acetamid0]phenol.-To a mixture of 2.3 g. (0.01 mole) of 6-amino-2,4-dichloro-3-methylphenol hydrochloride and 2.5 g. (0.03 mole) of anhydrous sodium acetate in 45 cc. of 90% acetic acid, was added 3.8 g. (0.01 mole) of a-(3-pentadecylphenoxy) acetyl chloride. The reaction was permitted to continue spontaneously for sevenminutes; then the mixture was heated externally to 53. When the mixture had cooled to 40, 50 cc. of water was added and the solid was collected and washed with water followed by a little methanol. The product was crystallized from a mixture of ether-petroleum ether giving a yield of 3.2 g., which melted, at 122-,4". Recrystallization from'acetonitrile raises the melting point to 129- Couplers Nos. 2 and 3 were made similarly tocoupler No. .1 Using respectively oi-(3-n-pentadecylphenoxy)-nbutyryl chloride and 'y- (3 -n-pentadecylphenoxy) n-butyryl chloride instead of 3-n-pentadecylphenoxy acetyl chloride.

Coupler No. 4 was made in the same way as coupler No. 1 of US. Patent 2,474,293 using 3-n-penta'decylphenol instead of 2,4-di-tert.-amylphenol. i

Coupler No. 5 was made as follows:

Z-caprylylamido-S-nitrophen0l.-To a solution of 15.4 g. (0.1 mole) of Z-amino-S-nitrophenol, and 26 g. (0.2 mole) of. quinoline in cc. of dioxane was'added, with stirring at 25 C., a solution of 17.8 g. (0.11 mole) of octanoyl chloride in 50 cc. of dioxane. The temperature rose rapidly to 35 C. and a clear amber reaction mixture resulted. This mixturewas leftto stand overnight at room temperature, after which time it was poured into 600 cc. of dilute hydrochloric acid. The solid product was filtered ofi, dried, and recrystallized from 300 cc. of toluene. I

5-amino-Z-aprylylamidophenoL-In a 500 cc. low pressure reduction bottle was placed a solution of 7 g. (0.025 mole) of 2-caprylylamido-S-nitrophenol in 100 cc. of dioxane. To this solution was added one part of Raney nickel catalyst, and the bottle was placed on the Parr hydrogenation apparatus. The hydrogen pressure was brought up to 50 lb. and shaking commenced. The reduction was complete after approximately one hour. The mixture was filtered, and the solution of the amine was used without isolation. A I Z-caprylamido-fi-[o -(jf-n pntadecylphenobcfi n bilt'yramido]dmflwlfi-a(3*11-pntadecylphenoxy)-buty1yl chlo- .azeotrope. reaction mixture was filteredandsucked dryon a Buchner funnel; 111116 yield of.- yellow product was 24, g. r (82% .M.P.,16'6-7 C. 1 r

. ride wasprepared in the same .way as'u-( 3-pentadecylphenoxy)acetyl chloride except that ethyl 'a-bromobutyrate, followed by saponification, was used instead ofsodium chloroacetate. To a solution of 6.25 g. (0.025 mole) of -hour at room temperature, and then poured into 1 l. of

dilute hydrochloric acid. The solid product was filtered off, dried, and recrystallized five times from approximately parts of acetonitrile to give a compound melt- ,Coupler No. 6 was inade inthe same way as coupler No. 90f US. Patent 2,600,788 using ot-(3-napentadecyl phenoxyyn butyryl chloride instead of fi-(2,4-di-tert.-

amlyphenoxy)propionyl chloride.

Coupler No. 7 was made in the same way as-coupler No. 7 of US. Patent 2,600,788'using oc-(3-n-pentadecylphenoxy)-n-'butyryl chloride instead of 2,4-di-tert.-amylphenoxy acetyl chloride. 7 i

Coupler. No. 8-.was made in the same way as coupler No.26 using 2,4,5-trichloro'aniline insteadof 2,4, 6-trichloroaniline. a Coupler No. 9 was:made-in .the same way as coupler No. 7 using 2,4,5-trichloroanilineinstead of 2,4,6-trichloroaniline.

Coupler No. 10 was prepared as follows:

u-(m-Nitrobenzoyl)-2-meth0xyacetartilide.-To a retfluxing mixture of 22 g. (.093 mole) of ethyl a-(m-nitro- 'benzoyD-acetate (Biilow and Hailer, Ber., 35, 915 (1902)) in 150 m1. of histological xylene was added in one portion 11 g. (.09 mole) ofo-anisi dine. The mixture was heatedat the reflux temperature (oil bath at 145-55 C.) ior two hours under a steam-jacketed stillhead, which permitted the removal.of the. alc0holxylene Theproduct which separated from: the cooled liter, threeg ecked flask, equipped with stirrer, reflux condenser and addition tube, wereplaced 104 g; of technical-grade sodium sulfide (0.8 mole) and 200 ml. of water.

The mixture-was, stirred gently on a steam bathvuntil solution was complete, and 3200rnl. of ethyl :alcohol were added. The mixture was boiled and 126 'g. (0.4 mole) of a-(m-nitrobenzoyl) -2-methoxyacetanilide were. added portionwise over a period of fifteen minuteswith good stirring. The brown reaction mixture was heated at the boiling point for one-half hour and poured on about an equal volume of ice. To the col-d solution was added 212 g. (4 moles) of solid ammonium chloride. The mixture,

was stirred manually until the ammonium chloride was dissolved, and allowed to stand for forty minutes. The product was filtered =by suction and washed on the funnel 'withseveraliliters of water, until the washingswere colorless. The pale-yellow product was dissolved in 1600 ml. or boiling alcohol and 100 ml. of hot water added; A

small amount ofDarco :was added, and the solution was filtered while hot The cooled filtrateyielded 89.1 g.

. tt rrsda ft t 1 heir 1 s.-(Olale)tet are-sad. r rh n x l- -h a th t d was:.ade d r n approximately one-half ,minute. -Thereaction mixture became. much thinner,:but failed to clear up asthetemperature rose'from 25.5 C. to 335 C.; color wasapinkgray. Following one :and one-half hours of stirring, :the mixture :was diluted dropwise over a period: of one-half hour with 30 cc. of water and seeded with coupler. Further stirring overnight .caused separation of product as a finely divided white mass.

The reaction mixture was drowned with stirring ,dur" g "fifteen minutes in 600 cc. ofwater the. product separating in white granules. Stirring wascontinued, for fortyfive minutes and the mixture filteredreadily ,through a S-inch Buchner funnel. The white solid was ,washed on the funnel with.2.liters of water,.not over 20' C. immediately, when the cake was no longer covered bywater,

it shrank in a characteristicmanner away tfromthe edge ofthe funnel as though threatening to become gummy. This change failed-to oocur as thecake sucked and pressed thoroughly. The solid, which-could :be-broken up easily, was air-dried, 60 g. being obtained; it had an indistinct melting range, starting at about C.

Twelve hundred cc. of cyclohexane was heated to a boil on the steam bath and the 60 g. of crude product dissolved therein,'cforn1ing a pink solution. It was treated with 2 g. of Darco and the solution-filtered hot through2 g. of Darco on a 4-inch Buchnerfunnel. Clear filtrate was only slightly less colored-than prior to the Darco treatment. The coupler was permitted to crystallize-undisturbed overnight. It was filtered readily,washed on the tunnelZw-ith three "-cc. portions ofr firesh cyclohexane. The yield was 47 g. (82% of the theoretical amount) of white coupler, which'meltedat 126-127 C.

. Coupler No. :11 was prepared as follows: '.a-Benzoyl-2-mthoxye5-nifioaceianilideL-Jn 'a" 250- 1. round bottom flask equipped with a 'partial condensing "stillhea'd were placed 100ml. 'ofhistological xylene and .50 ml. of-xylene, and finally with 100 .ml. ofpetroleum 45 ether. A crude yield of 26 grams. (83 percent) was obtained which melted at 170-175 'C. 'On recrystallization from 18 parts of glacial acetic acid, 22.4 grams: (7.1 percent) of finelight yellow needles, M.P. 177-17956, was obtained. i

..a-Bengoyl-5-amin0 2-meth0xyacetanilide.+-In a Parr hydrogenation bottle werepla'ced 1.6 grams (0,051 mole) of "'a-benzoyl-2-methoxy 5-nitroacetanilide, 250 of absolute ethyl alcohol, and Z-S'Lgrams er R'aney; nickel.

The reaction mixture was shaken under 2-3 atmospheres of hydrogen'overnight atroom temperature. The nickel was removed by filtration and the filtrate cooled in an ice bath. 'The light yellow solid was filtered, washed with 50 ml. of cold methyl alcohol, and dried. The yieldwas 13 grams (90 percent) of a solid which melted at 108- 110 C.

3 benzoylacetamino 4 methoxy (2.,4' diltert.- amylphenoxy) acetanilide.-In ,a 250-ml. Erlenmeyer flask were placed 5.68 grams (0.02 mole) of ot-benzoyl- S-amino-2-methoxyacetanilide, 2 grams (0.02-I- mole) of anhydrous sodium acetate, and 100 ml. of ,glacial acetic acid. With good stirring 6.2 grams,l(0.02, mole) of e-(3-n-pentadecylphenoxy) mbutyryl chloride. in 25 .ml. of glacial acetic acid was added allat once. The reaction mixture was stirred 1 hour at room temperatureand /2 hour at 60 C. After cooling to room temperature, the reaction mixture was pouredwith vigorousstirring eld s 7- em P ai a r vdwwhk 'by 2 cc. of tri-o-cresyl phosphate.

. '7 melted at 124- 126 C. Recrystallization from 200 ml. ofgalcohol gave 6.2 grams (55%) of a product which melted at 132134 C.

"the 'acid chloride with the coupler amine (6-amino-2,4-

dichloro-3-methylphenol) in the presence of a sodium acetate-acetic acid buffer gave the coupler, melting at '14'1-2. Recrystallization from glacial acetic acid raised 'the' melting point to 141.5-142'7.

The lowering of-the-rnelting points of the couplers by the normal alkyl group, compared with the corresponding compound containing a tertiary or branch chain group is shown in the following table:

I Mn, c. Coupler No. la 141.5-142 Same coupler with tert. octyl group 149-152 The following example illustrates the incorporation of Example One. gram of coupler No. 1 was dissolved by warming This solution was combined with a mixture of 50 cc. of 10% gelatin solution, cc. of' 5% .Alkanol B solution and 30 cc. of distilled water, and the whole passed through a colloid mill several times. To the resulting dispersion-was added 20 of a gelatino-silver halide emulsion and the mixture was coated in the usual manner.

After exposure, this'emulsion was developed in the following solution:

. Grams 2-amino-5-diethylaminotoluene HCl 2 .Sodium sulfite" (desiccated) 2 Sodium carbonate, 'mouohydrate 20 Potassium bromide 2 Water to 1 liter..

After development, the emulsion was fixed in the usual acid-alum fixing bath,' washed, and the silver removed by successive treatments in ferricyanide-bromide solution and hypo.

mg coupler containing atertiary alkyl group could be dissolved to the extent of 1 gram in 1 cc. of the coupler solvent only by raising the temperature to 115 C. Couplers containing the monoalkyl phenoxy groups are therefore, more soluble, than. those containing tertiary alkyl groups. These higher solubilities permit higher concentrations of couplers in coupler solvent to be used in the coatings and results in higher dye densities in the emulsion coatings.

' In addition to incorporating the coupler in the emulsion as described above, our couplers may also advantageously be incorporated in the emulsion as described in "Fierke and Chechak Patent 2,801,171. This method involves the preparation of low coupler-to-couplersolvent ratio dispersion. The coupler is first dissolved in either a low-boiling water-insoluble organic solvent or an appreciably water-solubleorg anic solvent with or without a high-boiling water-insoluble organic solvent,, the solution dispersed in gelatin and the dispersion chilled and set and at least of the water and substantially all of the low-boiling water-insoluble solvent or the appreciably water-soluble organic solvent removed. When emulsions made in this way are exposed and color developed, the

dye density is usually higher than that obtained from the emulsions made in the manner described in the example above.

In addition to being incorporated in gelatino-silver halide emulsion layers, our couplers may be incorporated in silver halide layers in which the emulsion carrier is an as paper or an opaque cellulose ester. The emulsion may be coated as a single layer on the support or superposed layers may be coated on one or both sides of the support. The superposed layersmay be differentially sensitized to form a natural color element in the known manner.

The examples and compounds set forth in the present specification are illustrative only and it is to be understood that our invention is to be taken as limited only by the scope of the appended claims.

We claim:

1. A color-forming photographic emulsion containing a color-forming compound of low dittusivity, comprising a gelatino-silver halide emulsion containing a color-forming compound selected from the class consisting of compounds having the structure and.

where Z is a color-forming group including an aryl radical, capable of coupling with the oxidation product of a primary aromatic amino developing agent, selected from the class consisting of phenolic hydroxyl, pyrazolone and benzoylacetamide groups, R is selected from the class consisting of hydrogen and an ethyl radical, R is a normal alkyl radical containing from 7 to 15 carbon atoms in a position selected from the class consisting of ortho, meta and para, and n is from 0 to 2.

2. A color-forming photographic emulsion containing a color-forming compound of low difiusivity, comprising a gelatino-silver halide emulsion containing a colorforming compound having the structure f o1 NHO0CH(C a)nO-C [CH3 7 R a color-forming compound of low difiusivity, comprising a gelatino-silver halide emulsion containing a colorforming compound having the structure where R is a normal alkyl radical containing "from 7 to 15 carbon atoms.

Q 7 nP 0tograpbic emulsion containing a color-forming compound of low difiusivity, comprising a gelatino-silver halide emulsion containing a color-forming compound having the structure 1 and R is a normal alkyl radical containing from 7 to carbon atoms.

5. A color-forming photographic emulsion containing a color-forming compound of low difiusivity, comprising a gelatino-silver halide emulsion containing a color-forming compound having the structure 01 NH00CH1O CH, O Hu-n 6. A color-forming photographic emulsion containing a color-forming compound of low diifusivity, comprising a gelatino-silver halide emulsion containing a color-forming compound having the structure on 01 NHGOoHQQ CH nHn-n 7. A color-forming photographic emulsion containing a color-forming compound of low diffusivity, comprising a gelatino-silver halide emulsion containing a color-forming compound having the structure 45 CIHI N (HQ-Cl 01 8. A color-forming photographic emulsion containing a color-forming compound of low diffusivity, comprising a gclatino-silver halide emulsion containing a color-forming compound having the structure @COCHaCONH-Q NHOOCHC2H5 OCH;

is n- 9. A color-forming photographic emulsion containing a color-forming compound of low diffusivity, comprising a gelatino-silver halide emulsion containing a color-forming compound having the structure 0-4: 0 CHzOONH References Cited in the file of this patent UNITED STATES PATENTS Wilmanns et al. Jan. 9, 1940 Bavley Aug. 12, 1947 McCrossen Sept. 15, 1953 Hanson Mar. 22, 1955 Loria et a1 Oct. 25, 1955 Whitmore Oct. 1, 1957 UNITED STATES PATE NT OFFICE Certificate of Co rrection Patent No. 2,908,573

October 13, 1959 Walter M. Bush et a1. It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 2, lines 42 to 47, the formula should appear as sho in the patent:

Cl I NBC 0 CHZO C 1aHa1-Il lines 33 to 36 inclusive, right-hand portion of the formula should appear as OW instead of as in the patent:

W11 below instead of as column 3, shown he] (0.5 ,7 read (015140 (1 this 7th day of June 1960.

column 7, line 9, for Signed and seale [SEAL] Attest KARL H. AXLIN E,

Commissioner of Patents. 

1. A COLOR-FORMING PHOTOGRAPHIC EMULSION CONTAINING A COLOR-FORMING COMPOUND OF LOW DIFFUSIVITY, COMPRISING A GELATINO-SILVER HALIDE EMULSION CONTAINING A COLOR-FORMING COMPOUND SELECTED FROM THE CLASS CONSISTING OF COMPOUNDS HAVING THE STRUCTURE 